Buelte Dorothee, Meister Ingo G, Staedtgen Mario, Dambeck Nina, Sparing Roland, Grefkes Christian, Boroojerdi Babak
Department of Neurology, RWTH Aachen University, Germany.
Brain Res. 2008 Jun 27;1217:110-8. doi: 10.1016/j.brainres.2008.03.075. Epub 2008 Apr 9.
Investigations in macaques and humans have shown that the anterior intraparietal sulcus (IPS) has an important function in the integration of information from tactile and visual object manipulation. The goal of this study was to investigate the special functional role of the anterior IPS in visuo-tactile matching in humans. We used the "virtual-lesion" technique of repetitive transcranial magnetic stimulation (rTMS) to test the functional relevance of anterior IPS for visuo-tactile crossmodal matching. Two crossmodal (visual encoding and tactile recognition and vice versa) and two unimodal delayed matching-to-sample tests with geometrical patterns were performed by 12 healthy subjects. We determined error rates before and after focal low-frequency rTMS applied over the left anterior IPS, right anterior IPS and vertex. During the manipulation of objects with the right hand, rTMS over the left anterior IPS induced a significant deterioration for visual encoding and tactile recognition, but not for tactile encoding and visual recognition. For the visual and tactile unimodal conditions, no significant alterations in task performance were found. rTMS application over right IPS when manipulating objects with the left hand did not affect crossmodal task performance. In conclusion, we have demonstrated an essential functional role of the left anterior IPS for visuo-tactile matching when manipulating objects with the right hand. However, we found no clear evidence for left IPS involvement in tactile encoding and visual recognition. The differential effect of rTMS on tactile and visual encoding and recognition are not consistently explained by previous concepts of visuo-tactile integration.
对猕猴和人类的研究表明，顶内沟前部（IPS）在整合触觉和视觉物体操作信息方面具有重要功能。本研究的目的是调查人类顶内沟前部在视觉-触觉匹配中的特殊功能作用。我们使用重复经颅磁刺激（rTMS）的“虚拟损伤”技术来测试顶内沟前部对视觉-触觉跨模态匹配的功能相关性。12名健康受试者进行了两项跨模态（视觉编码和触觉识别，反之亦然）以及两项使用几何图案的单模态延迟样本匹配测试。我们测定了在左侧顶内沟前部、右侧顶内沟前部和头顶施加局灶性低频rTMS前后的错误率。在用右手操作物体时，对左侧顶内沟前部进行rTMS会导致视觉编码和触觉识别显著恶化，但对触觉编码和视觉识别没有影响。对于视觉和触觉单模态条件，未发现任务表现有显著变化。在用左手操作物体时，对右侧顶内沟进行rTMS不影响跨模态任务表现。总之，我们证明了在用右手操作物体时，左侧顶内沟前部在视觉-触觉匹配中具有重要功能作用。然而，我们没有发现明确证据表明左侧顶内沟参与触觉编码和视觉识别。rTMS对触觉和视觉编码及识别的不同影响无法用先前的视觉-触觉整合概念得到一致解释。
